Calculate Your Ideal Body Weight Using Multiple Scientific Formulas
Your Ideal Body Weight Range
Ideal Body Weight (IBW) is an estimate of the optimal weight for your height and gender based on scientific formulas developed by medical researchers. Unlike Body Mass Index (BMI), which provides a range, IBW gives you a specific target weight that has been associated with optimal health outcomes, reduced disease risk, and improved longevity.
Understanding your ideal weight helps with setting realistic weight management goals, calculating medication dosages in medical settings, determining appropriate calorie intake, and assessing your current health status. However, IBW formulas don't account for individual factors like muscle mass, bone density, or body frame size, so they should be used as general guidelines rather than absolute targets.
This calculator uses five widely-accepted formulas to provide a comprehensive range of ideal weight estimates. Each formula was developed through different research methodologies and populations, which is why results vary slightly.
Devine Formula (1974) - Most Widely Used:
Developed by Dr. B.J. Devine for calculating drug dosages, this is the most popular and medically validated formula. It's used in hospitals worldwide for medication calculations and nutritional assessments.
Robinson Formula (1983):
A modification of the Devine formula that generally produces slightly higher weights for taller individuals and slightly lower weights for shorter people.
Miller Formula (1983):
Another Devine modification that typically yields higher baseline weights but smaller increments per inch of height.
Hamwi Formula (1964):
Originally created for quick medication dosage calculations, this formula tends to produce results similar to Devine for average heights.
Your ideal weight calculation provides multiple estimates because different formulas were developed for different purposes and populations. The range between these formulas typically spans 5-15 pounds (2-7 kg), which is considered normal variation.
| Height | Men (Ideal Weight) | Women (Ideal Weight) |
|---|---|---|
| 5'0" (152 cm) | 106-110 lbs (48-50 kg) | 100-105 lbs (45-48 kg) |
| 5'2" (157 cm) | 116-120 lbs (53-54 kg) | 110-115 lbs (50-52 kg) |
| 5'4" (163 cm) | 126-130 lbs (57-59 kg) | 120-125 lbs (54-57 kg) |
| 5'6" (168 cm) | 136-140 lbs (62-64 kg) | 130-135 lbs (59-61 kg) |
| 5'8" (173 cm) | 146-151 lbs (66-68 kg) | 140-145 lbs (64-66 kg) |
| 5'10" (178 cm) | 156-161 lbs (71-73 kg) | 150-155 lbs (68-70 kg) |
| 6'0" (183 cm) | 166-171 lbs (75-78 kg) | 160-165 lbs (73-75 kg) |
| 6'2" (188 cm) | 176-182 lbs (80-83 kg) | 170-175 lbs (77-79 kg) |
These ranges represent averages across the major formulas (Devine, Robinson, Miller, Hamwi). Individual ideal weights may vary based on body composition, frame size, and muscle mass.
While IBW provides a single target, health experts typically recommend aiming for a healthy weight range rather than a specific number. A healthy range is generally considered to be ±10% of your ideal body weight. For example:
This range accounts for natural variations in body composition, frame size, and individual physiology while still maintaining optimal health outcomes.
Both Ideal Body Weight and Body Mass Index are tools for assessing healthy weight, but they serve different purposes and have distinct advantages and limitations.
| Aspect | Ideal Body Weight (IBW) | Body Mass Index (BMI) |
|---|---|---|
| What It Measures | Target weight for height and gender | Weight relative to height ratio |
| Result Type | Specific weight in kg or lbs | Numerical score with categories |
| Gender Difference | Yes, different formulas for each | Same calculation for all genders |
| Accounts for Age | No (most formulas) | No |
| Medical Use | Drug dosing, nutrition assessment | Population health screening |
| Best For | Setting specific weight goals | Quick health risk assessment |
| Limitation | Doesn't consider body composition | Doesn't distinguish muscle from fat |
For comprehensive health assessment, both IBW and BMI calculations should be used together along with body composition measurements, waist circumference, and overall health markers.
While IBW formulas provide scientifically-based estimates, several individual factors can influence what weight is truly "ideal" for your body and health goals.
People with larger bone structures and broader frames naturally weigh more than those with smaller frames, even at the same height. Frame size can add or subtract 10-20 pounds from your ideal weight calculation. To estimate frame size, wrap your thumb and middle finger around your wrist:
Muscle tissue is denser than fat tissue, meaning muscular individuals can weigh more while still being healthy. Athletes, bodybuilders, and highly active people may exceed their IBW by 15-30 pounds due to muscle mass while maintaining low body fat percentages. In these cases, body fat percentage and BMR measurements are more accurate health indicators than IBW.
While most IBW formulas don't account for age, research suggests that slightly higher weights may be healthier for older adults (65+). Some experts recommend adding 5-10 pounds to calculated IBW for seniors to maintain adequate nutrient reserves and bone density. Conversely, younger adults (18-25) may target the lower end of their IBW range.
IBW formulas were primarily developed using Western populations and may not be as accurate for all ethnic groups. Asian populations typically have optimal health at weights 5-10% lower than standard IBW calculations, while some Pacific Islander populations may have higher optimal weights. Cultural and genetic variations in body composition should be considered.
Certain medical conditions affect ideal weight targets:
Achieving your ideal weight requires a sustainable, evidence-based approach that prioritizes both physical health and mental well-being. Here are proven strategies for reaching and maintaining your target weight.
Safe, sustainable weight loss is 0.5-2 pounds per week (0.25-1 kg), which means reaching your ideal weight might take several months or even years depending on your starting point. Calculate your timeline: if you're 40 pounds from your ideal weight, expect 20-40 weeks of consistent effort. Breaking this into smaller milestones (10-pound increments) makes the journey more manageable and motivating.
Example Weight Loss Timeline:
Use your BMR (Basal Metabolic Rate) to determine your total daily energy expenditure (TDEE), then create a moderate calorie deficit of 300-500 calories per day for weight loss, or a surplus of 250-500 calories for healthy weight gain. Never eat below your BMR for extended periods, as this can slow metabolism and cause muscle loss.
Prioritize whole, nutrient-dense foods that support satiety and energy:
Resistance training 2-4 times per week builds or preserves muscle mass during weight loss, increases metabolic rate, and improves body composition. Focus on compound movements (squats, deadlifts, presses, rows) and progressive overload. Even at your ideal weight, higher muscle mass creates a leaner, more toned appearance.
Include 150-300 minutes of moderate cardio weekly (walking, cycling, swimming) or 75-150 minutes of vigorous activity (running, HIIT, sports). Cardio burns calories, improves heart health, and enhances mood. Mix steady-state and interval training for best results.
Track multiple indicators of progress:
Aim for 80-90% adherence to your nutrition and exercise plan rather than perfection. Occasional indulgences, social events, and rest days are part of sustainable healthy living. Focus on long-term habits rather than short-term restriction. If you have a "off" day or week, simply return to your routine without guilt or compensation behaviors.
Reaching your ideal weight is an achievement, but maintaining it long-term requires ongoing commitment and strategies to prevent weight regain, which affects 80-95% of dieters who use restrictive methods.
Once you reach your goal weight, gradually increase calories by 100-200 per week until you're eating at your new maintenance level (your TDEE at the lower weight). This reverse dieting approach helps restore metabolic rate and prevents sudden weight regain. Monitor your weight weekly and adjust if you see increases beyond normal 2-3 pound fluctuations.
Maintain your exercise routine with 3-5 workouts per week combining strength training and cardio. Exercise becomes even more important in maintenance to preserve muscle mass, regulate appetite hormones, and allow dietary flexibility. People who maintain weight loss long-term typically exercise 200-300 minutes weekly.
Weigh yourself once per week on the same day, time, and conditions. If weight increases 5+ pounds above your goal for 2 consecutive weeks, immediately return to a small calorie deficit (200-300 calories) until you're back in range. Early intervention prevents large regains that are harder to reverse.
Long-term success requires lifestyle changes, not temporary diets:
Rather than rigidly maintaining one specific weight, establish a 5-pound "maintenance range" (e.g., 155-160 lbs). This accounts for natural fluctuations from water retention, hormonal cycles, travel, and occasional indulgences while keeping you within your healthy weight zone. This flexibility reduces stress and is more sustainable long-term.
Ideal Body Weight formulas are useful guidelines for the general population, but certain groups should use alternative metrics or work with healthcare professionals for personalized targets.
Standard IBW formulas significantly underestimate healthy weights for athletes and bodybuilders. A 6'0" male bodybuilder might have an IBW calculation of 178 lbs but weigh 210+ lbs at 8-12% body fat. For these individuals, body composition testing (DEXA scans, hydrostatic weighing, or bioelectrical impedance) and body fat percentage targets (10-20% for men, 18-28% for women) are more appropriate than IBW.
IBW formulas were developed for adults and should not be used for anyone under 18. Growing children and teens require age and development-specific growth charts (CDC or WHO charts) that compare height and weight percentiles relative to peers. Pediatricians use BMI-for-age percentiles and growth velocity rather than fixed ideal weights.
Pregnancy requires weight gain above pre-pregnancy IBW to support fetal development and maternal health. Recommended pregnancy weight gain varies based on starting BMI: underweight women should gain 28-40 lbs, normal weight 25-35 lbs, overweight 15-25 lbs, and obese 11-20 lbs. Breastfeeding women should maintain pre-pregnancy weight plus nutrient reserves, not diet to reach IBW until after weaning.
Research suggests that being slightly overweight (5-15 lbs above IBW) may be protective for elderly adults, providing reserves during illness and supporting bone density. Unintentional weight loss in seniors is associated with increased mortality, frailty, and functional decline. Older adults should prioritize maintaining weight and muscle mass rather than pursuing lower ideal weights.
For those recovering from anorexia, bulimia, binge eating disorder, or other eating disorders, focusing on a specific "ideal weight" can be triggering and counterproductive to recovery. Treatment teams typically use individualized weight restoration goals based on metabolic recovery, bone density, hormone function, and psychological factors rather than IBW formulas.
IBW formulas assume intact limbs and typical body structure. Individuals with amputations need adjusted formulas that account for missing limb weight: lower leg (~6% body weight), upper leg (~16%), entire leg (~18%), lower arm (~3%), upper arm (~3%), entire arm (~6%). Those with paraplegia or quadriplegia may have altered muscle mass distributions requiring individualized assessment.
Beyond personal fitness goals, Ideal Body Weight calculations serve important roles in clinical medicine and healthcare settings.
Many medications, especially anesthetics, chemotherapy drugs, and antibiotics, are dosed based on IBW rather than actual body weight to avoid overdosing in obese patients or underdosing in underweight patients. For obese patients (>30% above IBW), doctors often use Adjusted Body Weight (ABW): IBW + 0.4 × (Actual Weight - IBW).
Dietitians and nutritionists use IBW to calculate appropriate calorie and protein targets for medical nutrition therapy. Percentage of IBW helps classify malnutrition severity: <70% IBW indicates severe malnutrition, 70-80% moderate malnutrition, 80-90% mild malnutrition, and 90-110% normal nutritional status.
In intensive care units, mechanical ventilator tidal volumes are calculated using predicted body weight (similar to IBW) rather than actual weight to prevent lung injury, especially in obese patients. This is based on research showing lung size correlates better with height than actual body weight.
Candidates for weight loss surgery are often evaluated based on how far they are from their IBW. Excess Body Weight (EBW) = Actual Weight - IBW. Bariatric surgery is typically considered when BMI ≥40 or BMI ≥35 with comorbidities, which usually means being 100+ lbs above IBW.
Some kidney function calculations use IBW or adjusted body weight rather than actual weight, particularly when estimating glomerular filtration rate (GFR) and creatinine clearance in obese or malnourished patients.
The Devine formula (1974) is the most widely used and medically validated formula for general populations. It's used in hospitals worldwide for medication dosing and nutritional assessments. However, no single formula is perfect for everyone. The Robinson and Miller formulas (both from 1983) are modifications of Devine that may be more accurate for certain heights. For best results, consider the average of multiple formulas as your target range rather than fixating on one specific number.
Different IBW formulas were developed by different researchers using various populations, methodologies, and purposes. Devine created his formula for drug dosing in 1974, while Robinson, Miller, and Hamwi developed theirs for different clinical applications in the 1960s-1980s. The variation between formulas typically ranges 5-15 pounds (2-7 kg) for the same person, which reflects legitimate scientific uncertainty about what constitutes "ideal" weight. Using multiple formulas gives you a more realistic weight range to target.
No, it's better to aim for a healthy weight range within ±10% of your calculated IBW. For example, if your IBW is 150 lbs, targeting 135-165 lbs is more realistic and sustainable than fixating on exactly 150 lbs. Your body naturally fluctuates 2-5 pounds daily due to water retention, food volume, and hormonal changes. Additionally, IBW formulas don't account for muscle mass, frame size, or body composition, so your personal "ideal" might be different from the calculated number. Focus on how you feel, your energy levels, health markers, and body composition rather than one specific scale number.
If you're more than 20% above or below your IBW, consult with a healthcare provider or registered dietitian for personalized guidance. Being significantly above IBW (overweight/obese) increases risks for heart disease, diabetes, and joint problems, while being significantly below IBW (underweight) can indicate malnutrition, hormonal imbalances, or underlying health conditions. Create realistic intermediate goals (losing or gaining 10-20 lbs at a time) rather than trying to reach IBW immediately. Safe weight change is 0.5-2 lbs per week, so reaching your ideal weight might take several months to years depending on your starting point.
Most IBW formulas don't account for age and use only height and gender. However, research suggests that optimal weights may increase slightly with age. Studies show that being slightly overweight (5-15 lbs above calculated IBW) may be protective for adults over 65, providing reserves during illness and supporting bone density. The formulas work best for adults aged 18-65. Children and adolescents should use age-specific growth charts, while elderly adults (70+) should focus on maintaining weight and muscle mass rather than pursuing lower ideal weights. Muscle mass naturally decreases with age (sarcopenia), so strength training becomes increasingly important.
IBW formulas significantly underestimate healthy weights for athletes, bodybuilders, and highly muscular individuals because they don't account for body composition. Muscle tissue is denser than fat, so muscular people can be 15-30+ pounds above their calculated IBW while having low body fat percentages. If you're very athletic or muscular, use body fat percentage targets instead: 10-20% for men, 18-28% for women. Body composition testing (DEXA scan, bod pod, bioelectrical impedance) provides much more accurate health assessment than IBW for athletic populations. Focus on how you look, feel, and perform rather than a number on the scale.
IBW calculators are reasonably accurate for average adults with typical body composition, providing estimates within ±10-15% for most people. They work best for adults aged 18-65 with average muscle mass and frame sizes. Accuracy decreases for athletes, elderly individuals, pregnant women, children, and those with certain medical conditions. The formulas were developed using predominantly Western populations and may be less accurate for some ethnic groups (Asian populations typically have optimal health at weights 5-10% lower than calculated IBW). Use IBW as a general guideline and starting point, but adjust based on your individual body composition, frame size, and how you feel at different weights.
"Ideal weight" refers to specific calculations from formulas like Devine or Robinson, while "healthy weight" is a broader range where you experience good health, energy, and reduced disease risk. Your healthy weight might be 5-20 pounds different from your calculated IBW depending on muscle mass, frame size, genetics, and individual factors. Someone might be "healthy" at 175 lbs even if their IBW is 160 lbs if they have high muscle mass and normal body fat percentage. Focus on health markers (blood pressure, cholesterol, blood sugar, energy levels, mood, sleep quality) rather than hitting one specific number. The best weight for you is one you can maintain sustainably while enjoying good physical and mental health.
Use both tools together for comprehensive assessment. BMI provides a health risk category (underweight, normal, overweight, obese) and works well for population-level screening, while IBW gives you a specific target weight to work toward. Neither is perfect alone: BMI doesn't account for muscle mass (may classify muscular athletes as overweight), and IBW doesn't account for frame size or body composition. Ideally, your weight should fall within both healthy BMI range (18.5-24.9) and within ±10% of your calculated IBW. If they conflict (e.g., you're muscular with high BMI but near IBW), use body fat percentage and health markers as tiebreakers. The best approach combines multiple measurements: weight, BMI, IBW, body fat percentage, waist circumference, and metabolic health markers.
Safe, sustainable weight change is 0.5-2 pounds per week for weight loss, or 0.5-1 pound per week for weight gain. Calculate your timeline by dividing the pounds needed by your weekly rate. Examples: If you're 40 lbs above IBW and lose 1.5 lbs/week, expect 27 weeks (6-7 months). If you're 20 lbs below IBW and gain 0.75 lbs/week, expect 27 weeks. Faster weight loss (3+ lbs/week) often leads to muscle loss and metabolic slowdown, while slower progress (0.25 lbs/week) may not provide enough motivation. Focus on consistent habits rather than speed. Remember that the last 10-15 pounds typically come off slower as you approach your goal weight. Be patient and prioritize sustainable methods over quick fixes.